Shalaka engineering noteshttps://shalaka.com/notes/Notes from the engineers at Shalaka Connected Devices LLPen-inAdding connectivity to an existing product through its serial porthttps://shalaka.com/notes/add-connectivity-through-serial-port/https://shalaka.com/notes/add-connectivity-through-serial-port/Sat, 14 Nov 2026 00:00:00 GMTHow to connect an instrument or machine that already works, without redesigning its main board: what to check, and where the approach stops working.AI agents with a person in charge: approval steps, logs and widening what an agent may dohttps://shalaka.com/notes/ai-agents-person-in-charge/https://shalaka.com/notes/ai-agents-person-in-charge/Sat, 14 Nov 2026 00:00:00 GMTHow to give an AI agent a narrow job, put an approval step in front of anything that leaves the building, keep a log, and widen its permissions with evidence.Asking your datasheets and test reports questions: what a document assistant gets right and wronghttps://shalaka.com/notes/asking-datasheets-test-reports-questions/https://shalaka.com/notes/asking-datasheets-test-reports-questions/Sat, 14 Nov 2026 00:00:00 GMTA document assistant can find the right page in a datasheet fast. Here is how retrieval, tables, scanned PDFs and invented numbers decide whether to trust it.BLE setup apps: why pairing is the most-reviewed screen in the apphttps://shalaka.com/notes/ble-setup-app-pairing-screen/https://shalaka.com/notes/ble-setup-app-pairing-screen/Sat, 14 Nov 2026 00:00:00 GMTOnboarding flow, Wi-Fi credential handover over BLE, error messages and Android and iOS permission differences that decide first-run success.BLE, Wi-Fi, LoRa or LTE Cat-1 for a product sold in Indiahttps://shalaka.com/notes/ble-wifi-lora-lte-cat1-india/https://shalaka.com/notes/ble-wifi-lora-lte-cat1-india/Sat, 14 Nov 2026 00:00:00 GMTHow to pick the radio for a connected product in India: range, power, data, running cost, networks and approvals. A short decision guide.BoM versus schematic checks before you order partshttps://shalaka.com/notes/bom-vs-schematic-checks-before-ordering/https://shalaka.com/notes/bom-vs-schematic-checks-before-ordering/Sat, 14 Nov 2026 00:00:00 GMTThe mismatches between a bill of materials and a schematic that waste a board spin, and the checks we run before any parts are ordered.Calibration tracking for instruments and gauges, before the audithttps://shalaka.com/notes/calibration-tracking-before-the-audit/https://shalaka.com/notes/calibration-tracking-before-the-audit/Sat, 14 Nov 2026 00:00:00 GMTWhat a calibration register must hold: due dates, certificates, traceability and out-of-tolerance handling, so no gauge is found overdue at an audit.Choosing a cellular module as 2G and 3G shrink in Indiahttps://shalaka.com/notes/choosing-cellular-module-india-2g-3g-shrinking/https://shalaka.com/notes/choosing-cellular-module-india-2g-3g-shrinking/Sat, 14 Nov 2026 00:00:00 GMTHow to pick between LTE Cat-1, Cat-M and NB-IoT for a new device in India, and which availability and certification questions to settle first.Dashboards a plant team actually opens every morninghttps://shalaka.com/notes/dashboards-plant-teams-open/https://shalaka.com/notes/dashboards-plant-teams-open/Sat, 14 Nov 2026 00:00:00 GMTWhy most IoT dashboards are visited twice and then ignored, and the design choices that make a plant team check one before the first shift meeting.Designing a board so a jig can test it in two minuteshttps://shalaka.com/notes/design-board-for-two-minute-test-jig/https://shalaka.com/notes/design-board-for-two-minute-test-jig/Sat, 14 Nov 2026 00:00:00 GMTTest points, a programming header, a bed-of-nails fixture and a short test sequence: how a board is laid out so production testing stays fast.Provisioning: how a device gets its identity at the factory or on sitehttps://shalaka.com/notes/device-provisioning-identity/https://shalaka.com/notes/device-provisioning-identity/Sat, 14 Nov 2026 00:00:00 GMTSerial numbers, per-device credentials, certificates and claiming a device to a customer account: how to give every unit its own identity safely.Downtime logging that operators actually usehttps://shalaka.com/notes/downtime-logging-operators-use/https://shalaka.com/notes/downtime-logging-operators-use/Sat, 14 Nov 2026 00:00:00 GMTHow to get honest downtime data from the shop floor: detect stops from machine data, ask for the reason with one tap, and keep the list short.Driving relays from a microcontroller: what to check before productionhttps://shalaka.com/notes/driving-relays-from-microcontroller/https://shalaka.com/notes/driving-relays-from-microcontroller/Sat, 14 Nov 2026 00:00:00 GMTGPIO current limits, flyback diodes, boot-time states and contact ratings. The relay checks we run on every mains-switching board.Edge or cloud for machine learning on sensor data: how to decidehttps://shalaka.com/notes/edge-or-cloud-for-sensor-ml/https://shalaka.com/notes/edge-or-cloud-for-sensor-ml/Sat, 14 Nov 2026 00:00:00 GMTFive questions on latency, bandwidth, privacy, power and updates that decide whether a sensor model runs on the device or in the cloud.ESD on exposed connectors and buttons: where the zap goeshttps://shalaka.com/notes/esd-protection-connectors-buttons/https://shalaka.com/notes/esd-protection-connectors-buttons/Sat, 14 Nov 2026 00:00:00 GMTHow IEC 61000-4-2 levels translate into TVS placement and return paths on a board, and what a TVS diode cannot fix on its own.ESP32 resets you only see on site: strapping pins and brown-outhttps://shalaka.com/notes/esp32-strapping-pins-brownout-resets/https://shalaka.com/notes/esp32-strapping-pins-brownout-resets/Sat, 14 Nov 2026 00:00:00 GMTTwo hardware causes behind 'random' ESP32 and ESP32-S3 resets in the field, and the checks we run before a board goes to fabrication.What an FFT on a microcontroller can and cannot tell you about a motorhttps://shalaka.com/notes/fft-microcontroller-motor-vibration/https://shalaka.com/notes/fft-microcontroller-motor-vibration/Sat, 14 Nov 2026 00:00:00 GMTVibration monitoring at the edge: what a MEMS accelerometer and an on-chip FFT can detect on rotating machines, and where you need more.Turning machine alarms into maintenance tickets with history attachedhttps://shalaka.com/notes/machine-alarms-to-maintenance-tickets/https://shalaka.com/notes/machine-alarms-to-maintenance-tickets/Sat, 14 Nov 2026 00:00:00 GMTHow to turn an alarm into one ticket with the machine's recent readings and past faults, so the technician starts with context and not a phone call.Setting a machine's baseline before calling anything an anomalyhttps://shalaka.com/notes/machine-baseline-before-anomaly/https://shalaka.com/notes/machine-baseline-before-anomaly/Sat, 14 Nov 2026 00:00:00 GMTAn anomaly alarm is only as good as the baseline behind it. How to collect one, handle operating modes, and set thresholds that do not cry wolf.Battery life on paper versus in the field: measuring sleep current properlyhttps://shalaka.com/notes/measure-sleep-current-battery-life/https://shalaka.com/notes/measure-sleep-current-battery-life/Sat, 14 Nov 2026 00:00:00 GMTHow to measure microamp sleep current without a burden voltage error, why wake bursts dominate the average, and how to calculate real battery life.Micro-app or ERP module: how to decide where a shop-floor task belongshttps://shalaka.com/notes/micro-app-or-erp-module/https://shalaka.com/notes/micro-app-or-erp-module/Sat, 14 Nov 2026 00:00:00 GMTFive questions we ask before choosing between an ERP module and a small purpose-built app for a shop-floor task, and the cases where the ERP should win.A morning energy report on WhatsApp: what to send and what to leave outhttps://shalaka.com/notes/morning-energy-report-on-whatsapp/https://shalaka.com/notes/morning-energy-report-on-whatsapp/Sat, 14 Nov 2026 00:00:00 GMTWhat a daily plant energy message should contain, how to keep it short, and what to know about WhatsApp Business API templates and opt-in.MQTT topic and payload design that still works at a thousand deviceshttps://shalaka.com/notes/mqtt-topics-and-payloads-at-scale/https://shalaka.com/notes/mqtt-topics-and-payloads-at-scale/Sat, 14 Nov 2026 00:00:00 GMTTopic hierarchy, QoS choice, retained messages, payload versioning and last will: the decisions that are cheap on day one and painful to change later.Offline-first shop-floor apps: keeping work going when the network dropshttps://shalaka.com/notes/offline-first-shop-floor-apps/https://shalaka.com/notes/offline-first-shop-floor-apps/Sat, 14 Nov 2026 00:00:00 GMTHow a shop-floor app keeps recording work when Wi-Fi fails: local storage, queued writes, conflict rules, and the records that must never be lost.One-step device provisioning at the end of the linehttps://shalaka.com/notes/one-step-device-provisioning-end-of-line/https://shalaka.com/notes/one-step-device-provisioning-end-of-line/Sat, 14 Nov 2026 00:00:00 GMTHow to write the serial number, credentials and cloud registration in a single operator action, and what to do when one of the three steps fails.OTA updates that cannot brick a devicehttps://shalaka.com/notes/ota-updates-that-cannot-brick/https://shalaka.com/notes/ota-updates-that-cannot-brick/Sat, 14 Nov 2026 00:00:00 GMTA/B slots, image verification, boot confirmation and rollback: how a firmware update can fail at any point, including power loss, and still leave a working device.From proof of concept to production: what has to changehttps://shalaka.com/notes/proof-of-concept-to-production/https://shalaka.com/notes/proof-of-concept-to-production/Sat, 14 Nov 2026 00:00:00 GMTA proof of concept answers whether something works. Production needs OTA updates, security, a test jig, sourcing and approvals. The list we work through.Quality checks with photos on a tablet: designing the checklist so it gets filled inhttps://shalaka.com/notes/quality-checks-with-photos-on-a-tablet/https://shalaka.com/notes/quality-checks-with-photos-on-a-tablet/Sat, 14 Nov 2026 00:00:00 GMTA tablet inspection checklist only helps if inspectors use it. Layout, photo rules, reject reasons and offline use that keep the records complete.What to ask a contract manufacturer before the first orderhttps://shalaka.com/notes/questions-for-contract-manufacturer/https://shalaka.com/notes/questions-for-contract-manufacturer/Sat, 14 Nov 2026 00:00:00 GMTQuestions on capability, testing, quality records, design feedback, minimum order quantity and traceability that separate a good build partner from a risky one.Reading Modbus energy meters: register maps, polling rates and byte orderhttps://shalaka.com/notes/reading-modbus-energy-meters/https://shalaka.com/notes/reading-modbus-energy-meters/Sat, 14 Nov 2026 00:00:00 GMTWhy two energy meters with the same Modbus registers can give different numbers, how fast you can really poll an RS485 bus, and how to handle counters.Why an RS485 link works on the bench and dies in the fieldhttps://shalaka.com/notes/rs485-link-dies-in-the-field/https://shalaka.com/notes/rs485-link-dies-in-the-field/Sat, 14 Nov 2026 00:00:00 GMTGround potential, surges and missing isolation: what kills RS485 links on site, and what we check on a schematic before the board is built.Shift handover summaries from machine events and operator noteshttps://shalaka.com/notes/shift-handover-summaries-from-machine-events/https://shalaka.com/notes/shift-handover-summaries-from-machine-events/Sat, 14 Nov 2026 00:00:00 GMTHow to turn overnight machine events and short operator notes into one page for the morning meeting, and where a person must still check it.Sourcing components in India: authorised distributors, lead times and counterfeit partshttps://shalaka.com/notes/sourcing-components-india/https://shalaka.com/notes/sourcing-components-india/Sat, 14 Nov 2026 00:00:00 GMTHow to spot counterfeit risk, why authorised distributors reduce it, and which lifecycle checks to run before a part goes on your bill of materials.Storing time-series data from devices without a large cloud billhttps://shalaka.com/notes/storing-device-time-series-cheaply/https://shalaka.com/notes/storing-device-time-series-cheaply/Sat, 14 Nov 2026 00:00:00 GMTSampling versus reporting rate, downsampling, retention tiers and compression: how to keep device data useful for years at a small and predictable cost.Tracking returned units by serial number so repeat faults show up earlyhttps://shalaka.com/notes/tracking-returned-units-by-serial-number/https://shalaka.com/notes/tracking-returned-units-by-serial-number/Sat, 14 Nov 2026 00:00:00 GMTHow a returns register tied to serial numbers and production batches shows repeat faults in weeks, and why symptom and root cause need separate fields.Vision on a production line: why lighting and camera position come before the modelhttps://shalaka.com/notes/vision-production-line-lighting-camera/https://shalaka.com/notes/vision-production-line-lighting-camera/Sat, 14 Nov 2026 00:00:00 GMTMost failed inspection projects fail on light and geometry, not on the neural network. What to fix and fix first before you train anything.Voice assistants for the shop floor: language, noise and what to loghttps://shalaka.com/notes/voice-assistants-shop-floor/https://shalaka.com/notes/voice-assistants-shop-floor/Sat, 14 Nov 2026 00:00:00 GMTWhat breaks when voice commands move from an office to a noisy plant: mixed languages, microphones, wake words, and what to record for improvement.Watchdogs: the settings that turn a hang into a clean restarthttps://shalaka.com/notes/watchdog-settings-clean-restart/https://shalaka.com/notes/watchdog-settings-clean-restart/Sat, 14 Nov 2026 00:00:00 GMTHardware and task watchdogs, where to feed them, how to pick a timeout, and how to log why the restart happened so the fault can be found.Watching your BoM for end-of-life and shortage notices before they stop productionhttps://shalaka.com/notes/watching-bom-for-eol-and-shortage-notices/https://shalaka.com/notes/watching-bom-for-eol-and-shortage-notices/Sat, 14 Nov 2026 00:00:00 GMTHow to track lifecycle status, PCN and EOL notices and stock for every BoM line, so a last-time buy or second source is decided before the line stops.What a production test station app should record for every unithttps://shalaka.com/notes/what-a-test-station-app-should-record/https://shalaka.com/notes/what-a-test-station-app-should-record/Sat, 14 Nov 2026 00:00:00 GMTThe fields a test station app should store for each serial number, from measured values and limits to firmware version and retest history, and why.What to log on a device so you can debug it from the officehttps://shalaka.com/notes/what-to-log-on-a-device/https://shalaka.com/notes/what-to-log-on-a-device/Sat, 14 Nov 2026 00:00:00 GMTReset reasons, event counters and RAM ring buffers: the small set of data that lets you diagnose a field failure without driving to site.Wide-input power for Indian sites: surges, brown-outs and generator changeovershttps://shalaka.com/notes/wide-input-power-surges-brownouts-generators/https://shalaka.com/notes/wide-input-power-surges-brownouts-generators/Sat, 14 Nov 2026 00:00:00 GMTHow to protect and design a power input for mains that sags, spikes and switches to a generator, with specifics on MOVs, TVS parts and hold-up time.WPC, TEC and BIS: which approvals a connected product may need in Indiahttps://shalaka.com/notes/wpc-tec-bis-approvals-india/https://shalaka.com/notes/wpc-tec-bis-approvals-india/Sat, 14 Nov 2026 00:00:00 GMTA general guide to what WPC, TEC and BIS each cover for connected hardware in India, and how to confirm what applies to your product.